Many different systems exist for delivering fuel into an engine's combustion chambers. For example, liquid and/or gaseous fuel can be directly injected into the combustion chamber, or indirectly injected into an upstream air passage and allowed to mix with air as the air enters the combustion chamber. In either situation, it can be a challenge to maximize combustion and/or fuel efficiency across all engine operating conditions while, at the same time, meeting emissions requirements associated with combustion exhaust. These challenges are amplified for applications in which more than one fuel is being combusted. For example, in such dual fuel applications, it can be difficult to optimize the amount of each fuel injected, as well as the timing of such injections, such that fuel efficiency is maximized. Additionally, dual fuel injection strategies directed toward maximizing fuel efficiency may not necessarily minimize levels of harmful pollutants present in engine exhaust.
The disclosed system is directed to overcoming one or more of the problems set forth above and/or other problems of the prior art.